The reliability of electromyographic (EMG) data has been examined for isometric and slow dynamic tasks, but little is known about the repeatability of this data for ballistic movements. The purpose of this study was to examine the within-session, trial-to-trial reliability of a variety of quadriceps and hamstrings muscles during isometric and ballistic activities. Data were analyzed by way of intraclass correlation coefficients (ICC), intersubject coefficients of variation (CVinter), and intrasubject coefficients of variation (CVintra). Twenty-four subjects performed 3 repetitions each of 2 randomly ordered test exercises, including landing from a depth jump (J) and cutting after a 10-m sprint (C). Data were acquired and processed with root mean square EMG for the muscles assessed, and data were analyzed for each exercise using a repeated measures analysis of variance. Results revealed that all ICC values were greater than 0.80, with most values greater than 0.90, CVinter values ranged from 5.4% to 148.7%, and CVintra values ranged from 11.5% to 49.3%. This study indicates that EMG is a reliable method for assessing the reproducibility of both the quadriceps and hamstrings muscle activation during either isometric or ballistic exercises.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1519/JSC.0b013e3181cc2353 | DOI Listing |
Int J Exerc Sci
December 2024
John G. Rangos, Sr. School of Health Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA.
The purpose was to summarize the studies examining knee strength in young athletes and provide valuable insights into the magnitude of changes in knee flexion and extension strength during the transition from pre-puberty to puberty among male and female athletes. The literature search was conducted through Cochrane Library, Embase, PubMed, Web of Science. Cohen's effect size (ES) and 95% confidence intervals (CIs) were computed using a random effects model.
View Article and Find Full Text PDFJ Sports Med Phys Fitness
January 2025
Physical Medicine and Rehabilitation Unit, Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.
Introduction: Sports injuries involving bi-articular muscles like the hip flexors, hamstrings, quadriceps, and gastrocnemius significantly affect athletes' performance and quality of life. Comprehensive rehabilitation is crucial for a pain-free return to play (RTP). Over the past 15 years, platelet-rich plasma (PRP) has emerged for its potential in tissue regeneration.
View Article and Find Full Text PDFBr J Sports Med
December 2024
Sahlgrenska Sports Medicine Center, Gothenburg, Sweden.
Objective: To evaluate the association between limb symmetry index (LSI) in quadriceps and hamstrings strength together with hop tests, as a proxy of recovery, and the deviation from being symmetrical (LSI 100%), with a safe return to sport (RTS) after anterior cruciate ligament reconstruction (ACL-R).
Methods: Athletes between 15 and 30 years old with a preinjury Tegner activity level ≥6 were eligible for inclusion. Data were extracted from a rehabilitation-specific registry, Project ACL (Gothenburg, Sweden) at the time of or after RTS for each athlete.
Asia Pac J Sports Med Arthrosc Rehabil Technol
January 2025
Department of Sports Medicine, Huashan Hospital, Fudan University, Shanghai, China.
Background: Persistent maladaptive changes of corticospinal tract (CST) and quadriceps strength deficits exist in patients with anterior cruciate ligament reconstruction (ACLR). This study aimed to investigate the relationships between the structural alterations of CST and quadriceps muscle strength deficits in patients with ACLR.
Methods: Twenty-nine participants who had undergone unilateral ACLR (29 males; age = 32.
BMC Musculoskelet Disord
January 2025
Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
Background: Ankle sprains often result in muscle atrophy and reduced range of motion, which can cause long-term ankle instabilities. Understanding the changes to muscle-such as atrophy-and concomitant changes to deep fascia-which may thicken alongside muscle loss-after ankle sprain injury is important to understanding structural changes about the joint and how they might contribute to longer-term impairments. Here, we employ advanced MRI to investigate skeletal muscle and fascial structural changes during the recovery period of one patient undergoing immobilization after ankle sprains.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!